Materials Literature
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Simple Monte Carlo multiple-trapping model simulations of the observed anomalous transit-time dispersion have been made. The model employs multiple trapping from an exponential distribution. Our results simulate the features of the experimental observations as well as provide a rational explanation for the transition…
A model is presented for the electronic properties of graphite intercalation compounds in the dilute limit, corresponding to intercalate concentrations more dilute than a stage-4 or -5 compound. In this limit, the electronic effect of intercalation in donor and acceptor compounds is modeled, respectively, as a raising…
Optical properties of polystyrene in the form of thin films were determined for photon energies between 0.6 and 82 eV from transmission measurements. The results for $k$, the extinction coefficient, were combined with previous experimental results in the soft and hard x-ray regions up to 8050 eV. Analyses were made on…
The heat capacity and resistivity at the charge-density-wave (CDW) transitions of several layered transition-metal dichalcogenides are presented. The magnitude of the thermal and resistive anomalies in the $2H$ polytypes indicates only a small fraction of the Fermi surface is involved in the CDW distortion. The transi…
Systematic x-ray photoelectron spectroscopy (XPS) measurements are reported for both core and valence electrons for oxides of the actinides thorium, uranium, neptunium, plutonium, americum, curium, berkelium, and californium. The XPS spectra of the localized $5f$ electron states were compared to the appropriate multip…
We have measured the second and third order hyperpolarizabilities of the three nitroaniline isomers and of two related molecules. For some isomers the intramolecular charge transfer is found to cause a very large enhancement of the second order polarizabilities. We present a theory relating this contribution to the fi…
The thermoluminescence glow curve of CaF 2 :Dy TLD-200 extends from room temperature up to about 450 degrees C. Dy 3+ is the main emitting centre for all the glow peaks. However, in addition to Dy 3+ emission, the glow peaks above 325 degrees C show four extrabands in the region 250-600 nm. Three of these are attribut…
The coexistence of the ferrimagnetic and the antiferromagnetic phases has been observed in the DyFeO 3 orthoferrite. The observations were made in a polarization microscope by means of the Faraday effect. Several features of the spin reorientation which shed some light on the mechanism of the transition, have been obs…
The mechanical behaviour of some metals has been investigated experimentally for compressive, tensile and torsional loading cycles of about 120 and 370 mu s duration and for steady-state loading in each of the three modes of deformation. For the dynamic measurements the split Hopkinson bar technique has been used in t…
The characteristics of the decay of the surface potential of corona-charged untreated polyethylene films 25 mu m thick in air have been investigated using a well-defined circular charging area and a high-resolution 80 mu m diameter induction probe. Distinct differences between the decay characteristics of negative and…
Strong experimental evidence is obtained that the maximum observed in the temperature dependence of the flow stress of copper alloys is a dislocation inertial effect. By using the superconducting effect in lead as a key, it is found that the maximum occurs when dislocations become critically damped.
In a time of growing need for catalysts, perovskites have been rediscovered as a family of catalysts of such great diversity that a broad spectrum of scientific disciplines have been brought to bear in their study and application. Because of the wide range of ions and valences which this simple structure can accommoda…
Guard hairs from normal mink and from normal and defective areas of mink pelts with “singe” or “red hip” abnormalities were studied with the scanning electron microscope (SEM). The surface or cuticle of normal guard hair consists of scales overlapping each other. These cuticle cells show regional variation in shape an…
Definition der Abreißbedingung durch das Kräftegleichgewicht am Flüssigkeitswulst. Messung der Gasgeschwindigkeit und der gasseitigen Grenzschichtdicke im Eindellungskrater. Daraus Berechnung der Reibungskraft sowie Berechnung der Schwerkraft und der Trägheitskraft. Ermittlung des kritischen Blaszustandes für den Begi…
In industrial electrostatic spray coating operations, liquid paint is applied to substrates of varying electrical characteristics. In many cases a metal substrate is chemically pretreated and/or primed prior to electrostatic spraying. A previously rejected part may have already received a number of thoroughly cured to…
The effect of γ-irradiation at room temperature on MgO powder samples has been investigated by thermoluminescence (TL) methods. In addition to a TL peak at 516 K, 'persistent' changes in the properties of lower temperature TL peaks have been observed in the irradiated samples. This includes mainly an increase in the s…
Effect of hydrostatic pressure on the ferroelectric phase transitions in glycine silver nitrate (NH 2 CH 2 COOH·AgNO 3 ; GSN) and its deuterated analogue(DGSN) was studied by means of dielectric measurements. The Curie temperatures decrease with increasing pressure by a relation T c = T c 0 + K p +γ p 2 . Parameters T…
1. Time resolved birefringence measurements reveal complex structural changes in rod outer segments following a bleaching flash. 2. The detailed character of the observed changes depends upon osmotic integrity of the outer segment envelope membrane. Rod outer segments with intact envelope membranes show a fast initial…
Abstract The atmospheric corrosion of a mild steel (0.09 C) has been studied in flowing atmospheres containing 1, 10 and 100ppm SO 2 at 80, 85, 90 and 96% relative humidity. The flow rate was varied to give SO 2 ‐supplies ranging between 0.4 and 250 μg SO 2 cm −2 h −1 . After an exposure period of 300 h testing was co…
The effect of irradiation temperature on irradiation-induced dislocation loops in copper has been studied by x-ray diffuse scattering. Dislocation loop size distributions and total defect concentrations were obtained for irradiations in the temperature range 316–483 °K for neutron doses in the range (1–10) ×1018 n/cm2…